The objectives of this project are determination of the structure, heterogeneity and points of attachment of the carbohydrate chains of Band 3 glycoprotein of the human erythrocyte membrane. Our goals for the current year include isolation of oligosaccharides from whole Band 3 and from the chymotryptic 17,000 dalton transmembrane fragment and estimation of the molecular weight of the oligosaccharides. We have used quantitative analysis to verify that these oligosaccharides are indeed representative of the glycoprotein free of amino acids. A second goal has been exploration of reversed phase HPLC as a method for determining heterogeneity of these oligosaccharides and for preparative fractionation.